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Query: EC:2.7.10.2 (
focal adhesion kinase
)
44,029
document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)
Ligand-dependent nuclear hormone receptor (NR) signaling requires direct interaction between NR and the steroid receptor coactivators (SRC). Herein we utilize a library of
SRC2
peptidomimetics to select for specific inhibitors of the interaction of
SRC2
with the two estrogen receptor (ER) isoforms, ERalpha and ERbeta, in the presence of three different ligands: 17beta-estradiol, diethylstilbesterol, and genistein. The pattern of inhibitor selectivity for each ER isoform varied depending upon which ligand was present, thus demonstrating that the ligands exert unique allosteric effects upon the surface of the SRC binding pocket. Several of the lead compounds are highly (>100-fold) selective for blocking the binding of
SRC2
to ERalpha, in preference to ERbeta, in the presence of one ligand and therefore may prove useful for decoupling ERbeta signaling from ERalpha signaling.
...
PMID:Ligand-selective inhibition of the interaction of steroid receptor coactivators and estrogen receptor isoforms. 1512 76
To clarify the genetic aberrations involved in the development and progression of hepatitis C virus-associated hepatocellular carcinoma (HCV-HCC), we investigated DNA copy number aberrations (DCNAs) in 19 surgically resected HCCs by conventional CGH and array CGH. Conventional CGH revealed that increases of DNA copy number were frequent at 1q (79% of the cases), 8q (37%), 6p (32%), and 10p (32%) and that decreases were frequent at 17p (79%), 16q (58%), 4q (53%), 13q (42%), 10q (37%), 1p (32%), and 8p (32%). In general, genes that showed DCNAs by array CGH were usually located in chromosomal regions with DCNAs detected by conventional CGH analysis. Increases in copy numbers of the LAMC2, TGFB2, and AKT3 genes (located on 1q) and decreases in copy numbers of
FGR
/
SRC2
and CYLD (located on 1p and 16q, respectively) were observed in more than 30% of tumors, including small, well-differentiated carcinomas. These findings suggest that these genes are associated with the development of HCV-HCC. Increases of MOS, MYC, EXT1, and
PTK2
(located on 8q) were detected exclusively in moderately and poorly differentiated tumors, suggesting that these alterations contribute to tumor progression. In conclusion, chromosomal and array CGH technologies allow identification of genes involved in the development and progression of HCV-HCC.
...
PMID:Analysis of DNA copy number aberrations in hepatitis C virus-associated hepatocellular carcinomas by conventional CGH and array CGH. 1513 72
Partial androgen insensitivity with sex phenotype variation in two unrelated families was associated with missense mutations in the androgen receptor (AR) gene that disrupted the AR NH(2)-terminal/carboxy terminal interaction. Each mutation caused a single amino acid change within the region of the ligand-binding domain that forms activation function 2 (AF2). In one family, the mutation I737T was in alpha helix 4 and in the other F725L was between helices 3 and 4. Neither mutation altered androgen binding as determined by assays of mutant AR in the patient's cultured genital skin fibroblasts or of recombinant mutant receptors transfected into COS cells. In transient cotransfection assays in CV1 cells, transactivation with the AR mutants at low concentrations of DHT was reduced several fold compared with wild-type AR but increased at higher concentrations. Defects in NH(2)-terminal/carboxy terminal interactions were identified in mammalian two hybrid assays. In similar assays, there was reduced binding of the p160 coactivators TIF2/
SRC2
and SRC1 to the mutant AR ligand binding domains (LBD). In the family with AR I737T, sex phenotype varied from severely defective masculinization in the proband to a maternal great uncle whose only manifestation of AIS was severe gynecomastia. He was fertile and passed the mutation to two daughters. The proband of the F725L family was also incompletely masculinized but was raised as a male while his half-sibling by a different father was affected more severely and reared as a female. These studies indicate that the function of an AR AF2 mutant in male development can vary greatly depending on the genetic background.
...
PMID:Partial androgen insensitivity with phenotypic variation caused by androgen receptor mutations that disrupt activation function 2 and the NH(2)- and carboxyl-terminal interaction. 1554 64
We previously reported that tumor necrosis factor alpha receptor- and Fas-associated FLASH interacts with one of the p160 nuclear receptor coactivators, glucocorticoid receptor-interacting protein (GRIP) 1, at its nuclear receptor-binding (NRB) domain, and that inhibits the transcriptional activity of the glucocorticoid receptor (GR) by interfering with association of GR and GRIP1. Here, we further examined the specificity of FLASH suppressive effect and the physical/functional interactions between this protein and two other p160 family subtypes. The suppressive effect of FLASH on GR transactivation was observed in several cell lines and on the chromatin-integrated mouse mammary tumor virus (MMTV) promoter. FLASH strongly interacted with the NRB domain of the thyroid hormone receptor activator molecule (TRAM) 1, a member of the steroid hormone receptor coactivator (SRC) 3/nuclear receptor coactivator (N-CoA) 3 subtypes, as well as with
SRC2
/N-CoA2 p160 coactivator GRIP1, while its interaction with SRC1a, one of the SRC1/N-CoA1 proteins, was faint in yeast two-hybrid assays. Accordingly, FLASH strongly suppressed TRAM1- and GRIP1-induced enhancement of GR-stimulated transactivation of the MMTV promoter in HCT116 cells, while it did not affect SRC1a-induced potentiation of transcription. Furthermore, FLASH suppressed androgen- and progesterone receptor-induced transcriptional activity, but did not influence estrogen receptor-induced transactivation, possibly due to their preferential use of p160 coactivators in HCT116 and HeLa cells. Thus, FLASH differentially suppresses steroid hormone receptor-induced transcriptional activity by interfering with their association with
SRC2
/N-CoA2 and SRC3/N-CoA3 but not with SRC1/N-CoA1.
...
PMID:FLASH interacts with p160 coactivator subtypes and differentially suppresses transcriptional activity of steroid hormone receptors. 1569 40
Using chromatin immunoprecipitation assays, we studied the 2,3,7,8-tetrachlorodibenzo-p-dioxin (TCDD)-mediated recruitment of the aryl hydrocarbon receptor (AhR) and several co-regulators to the CYP1A1 promoter. AhR displayed a time-dependent recruitment, reaching a peak at 75 min and maintaining promoter occupancy for the remainder of the time course. Recruitment of AhR was followed by TIF2/
SRC2
, which preceded CBP, histone H3 acetylation, and RNA polymerase II (RNAPII). Simultaneous recruitment to the enhancer and the TATA box region suggests the formation of a large multiprotein complex bridging the two promoter regions. Interestingly, estrogen receptor alpha (ERalpha) displayed a TCDD- and time-dependent recruitment to the CYP1A1 promoter, which was increased by co-treatment with estradiol. Transfection in HuH7 human liver cells confirmed previously reported ERalpha enhancement of AhR activity. In contrast, TCDD did not induce the recruitment of ERalpha to the estrogen-responsive pS2 promoter, and after 120 min of co-treatment with estradiol, ERalpha is still present on the CYP1A1 promoter but no longer at pS2. RNA interference studies with T47D cells support a role for ERalpha in TCDD-dependent CYP1A1 expression. Our data suggest that ERalpha acts as a coregulator of AhR-mediated transcriptional activation and that the recruitment of ERalpha by AhR represents a novel mechanism AhR-ERalpha cross talk.
...
PMID:Aryl hydrocarbon receptor-mediated transcription: ligand-dependent recruitment of estrogen receptor alpha to 2,3,7,8-tetrachlorodibenzo-p-dioxin-responsive promoters. 1596 90
In plant cells, certain membrane proteins move by unknown mechanisms directly from the endoplasmic reticulum (ER) to prevacuolar or vacuole-like organelles where membrane is internalized to form a dense, lattice-like structure. Here, we identify a sequence motif, PIEPPPHH, in the cytoplasmic tail of a membrane protein that directs the protein from the ER to vacuoles where it is internalized. A type II membrane protein in Arabidopsis thaliana, (At)
SRC2
(for Soybean Gene Regulated by Cold-2), binds specifically to PIEPPPHH and moves from the ER to the same vacuoles where it is internalized. Not all proteins that move in this pathway are internalized because another Arabidopsis type II membrane protein, (At)VAP (for Vesicle-Associated Protein), localizes to the same organelles but remains exposed on the limiting membrane. The identification of (At)
SRC2
and its preference for interaction with a targeting motif specific for the ER-to-vacuole pathway may provide tools for future dissection of mechanisms involved in this unique trafficking system.
...
PMID:Selective membrane protein internalization accompanies movement from the endoplasmic reticulum to the protein storage vacuole pathway in Arabidopsis. 1622 54
The acute-phase response (APR) leads to alterations in lipid metabolism and type II nuclear hormone receptors, which regulate lipid metabolism, are suppressed, in liver, heart, and kidney. Here, we examine the effect of the APR in adipose tissue. In mice, lipopolysaccharide produces a rapid, marked decrease in mRNA levels of nuclear hormone receptors [peroxisome proliferator-activated receptor gamma (PPARgamma), liver X receptor alpha (LXRalpha) and LXRbeta, thyroid receptor alpha (TRalpha) and TRbeta, and retinoid X receptor alpha (RXRalpha) and RXRbeta] and receptor coactivators [cAMP response element binding protein, steroid receptor coactivator 1 (SRC1) and
SRC2
, thyroid hormone receptor-associated protein, and peroxisome proliferator-activated receptor gamma co-activator 1alpha (PGC1alpha) and PGC1beta] along with decreased expression of target genes (adipocyte P2, phosphoenolpyruvate carboxykinase, glycerol-3-phosphate acyltransferase, ABCA1, apolipoprotein E, sterol-regulatory element binding protein-1c, glucose transport protein 4 (GLUT4), malic enzyme, and Spot14) involved in triglyceride (TG) and carbohydrate metabolism. We show that key TG synthetic enzymes, 1-acyl-sn-glycerol-3-phosphate acyltransferase-2, monoacylglycerol acyltransferase 1, and diacylglycerol acyltransferase 1, are PPARgamma-regulated genes and that they also decrease in the APR. In 3T3-L1 adipocytes, tumor necrosis factor-alpha (TNF-alpha) significantly decreases PPARgamma, LXRalpha and LXRbeta, RXRalpha and RXRbeta, SRC1 and
SRC2
, and PGC1alpha and PGC1beta mRNA levels, which are associated with a marked reduction in receptor-regulated genes. Moreover, TNF-alpha significantly reduces PPAR and LXR response element-driven transcription. Thus, the APR suppresses the expression of many nuclear hormone receptors and their coactivators in adipose tissue, which could be a mechanism to coordinately downregulate TG biosynthesis and thereby redirect lipids to other critical organs during the APR.
...
PMID:Type II nuclear hormone receptors, coactivator, and target gene repression in adipose tissue in the acute-phase response. 1684 10
Estrogen (E2) is involved in mediating many important functions relevant to osteoblast biology through the actions of the estrogen receptors (ER) alpha and beta. To further understand the mechanisms of ER-specific regulation, we used microarray and reverse transcription-PCR analyses of E2-treated U2OS-ERalpha or -ERbeta cells and identified retinoblastoma-binding protein 1 (RBBP1) as a major E2-regulated gene. RBBP1 is a retinoblastoma cofactor involved in the control of osteoblastic proliferation. Although RBBP1 mRNA levels rapidly increased after 2 h of E2 treatment in both U2OS-ER-expressing lines, a sustained induction was only observed in U2OS-ERalpha cells. Examination of the RBBP1 genomic sequence revealed an ER response element and a Sp1 site located within the first intron. Chromatin immunoprecipitation analyses demonstrated that E2-dependent ERalpha binding to the intron 1 enhancer region was constitutive, whereas ERbeta binding was transient, consistent with the mRNA time course. Interestingly, transient transfection and receptor mutational studies revealed that RBBP1 induction by ERalpha only requires the Sp1 site, whereas ERbeta utilizes both the Sp1 and estrogen response elements binding sites for maximal E2-dependent activation. Stable U2OS transfectants containing a deletion of the ERalpha activation function 1 (AF1) resulted in a temporal mRNA induction profile similar to that of wild type ERbeta. Further, overexpression and chromatin immunoprecipitation analyses also demonstrated that E2-dependent RBBP1 induction is
SRC2
-dependent for both ER isoforms. These results describe an E2-dependent, ER isoform-specific transcriptional activation of the RBBP1 gene, which in part, is explained by the differential activity of ER AF1 and enhancer element binding.
...
PMID:Estrogen receptor isoform-specific regulation of the retinoblastoma-binding protein 1 (RBBP1) gene: roles of AF1 and enhancer elements. 1687 70
Hepatocyte nuclear factor 4alpha (HNF4alpha) plays critical roles during liver development and in the transcriptional regulation of many hepatic genes in adult liver. Here we have demonstrated that in human hepatoma HepG2 cells, HNF4alpha is expressed at levels as high as in human liver but its activity on target genes is very low or absent. We have discovered that the low expression of key coactivators (PGC1alpha, SRC1,
SRC2
, and PCAF) might account for the lack of function of HNF4alpha in HepG2 cells. Among them, PGC1alpha and SRC1 are the two most important HNF4alpha coactivators as revealed by reporter assays with an Apo-CIII promoter construct. Moreover, the expression of these two coactivators was found to be down-regulated in all human hepatomas investigated. Overexpression of SRC1 and PGC1alpha by recombinant adenoviruses led to a significant up-regulation of well characterized HNF4alpha-dependent genes (ApoCIII, ApoAV, PEPCK, AldoB, OTC, and CYP7A1) and forced HepG2 cells toward a more differentiated phenotype as demonstrated by increased ureogenic rate. The positive effect of PGC1alpha was seen to be dependent on HNF4alpha. Finally, insulin treatment of human hepatocytes and HepG2 cells caused repression of PGC1alpha and a concomitant down-regulation of ApoCIII, PEPCK, AldoB, and OTC. Altogether, our results suggest that SRC1, and notably PGC1alpha, are key coactivators for the proper function of HNF4alpha in human liver and for an integrative control of multiple hepatic genes involved in metabolism and homeostasis. The down-regulation of key HNF4alpha coactivators could be a determinant factor for the dedifferentiation of human hepatomas.
...
PMID:Underexpressed coactivators PGC1alpha and SRC1 impair hepatocyte nuclear factor 4 alpha function and promote dedifferentiation in human hepatoma cells. 1689 7
Because RXR plays a significant role in nuclear receptor signaling as a common heterodimeric partner for TR, PPAR, RAR, VDR, LXR and others, the ability of RXRbeta ligand binding domain (LBD) to interact with coregulator peptides bearing LXXLL or other interaction motifs was investigated using time-resolved fluorescence resonance energy transfer (TR-FRET). The random phage display peptide D22 and peptides derived from PGC1alpha, SRC1-4,
SRC2
-3, PRIP/RAP250 and RIP140 yielded the highest TR-FRET signal with RXRbeta LBD in the presence of saturating 9-cis retinoic acid (9-cisRA). Several peptides including D22, PGC1alpha, SRC3-2, PRIP/RAP250 and SRC1-4 also formed a complex with RXRbeta LBD in the presence of all-trans retinoic acid (at-RA) and the fatty acids, phytanic acid (PA) and docosahexaenoic acid (DHA). Determination of the dose dependency (EC50) of these compounds to recruit D22 to RXRbeta LBD indicated that the rank order potency was 9-cisRA>PA>at-RA>DHA. The ligands 9-cisRA and at-RA yielded an overall higher fold-change in D22 recruitment to RXRbeta LBD suggesting that more RXRbeta LBD-D22 complex was formed in the presence of these ligands under the assay conditions tested. The statistical parameter Z' factor for 9-cisRA-induced recruitment of D22 to RXRbeta LBD was 0.6 after 2h incubation, indicating a robust methodology that could be applied to high throughput screening. These results demonstrate that RXRbeta occupied with the fatty acid ligands, DHA and PA, can recruit coactivator peptides in a ligand-dependent manner.
...
PMID:Analysis of ligand-dependent recruitment of coactivator peptides to RXRbeta in a time-resolved fluorescence resonance energy transfer assay. 1718 7
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